epadmin-tunable

epadmin tunable target — Manages the tunable variables for an EventFlow engine.

SYNOPSIS

epadmin [globalparameters] command tunable [commandparameters]

DESCRIPTION

Use the tunable target to manage the tunable variables for the StreamBase Runtime. Variables set using the tunable target are valid only until a node or engine is stopped. Supported tunable variables are defined in Supported Tunable Variables.

The full name of a tunable variable is categoryName.variableName, such as flusher.flushIntervalSeconds, where flusher is the category name and flushIntervalSeconds is the variable identifier.

The tunable target has three commands:

The designation [sn|ad] in syntax examples is a reminder that this command requires either the global parameter ‑‑servicename or the ‑‑adminport and ‑‑hostname combination to identify the node or cluster of interest.

Supported Tunable Variables

The column headings have the following meanings:

  • Category — Variable category.

  • Variable Identifier — Variable identifier.

  • Scope — Variable scope. A variable is scoped either to a node, or a specific engine running on a node. Node scope is specified with a literal value of Node, while engine scope is specified using the engine name expressed in the form application::engineName as shown in the output of get tunable. For example, application::JVMEngine1.

  • Description — Variable description.

Category Variable Identifier Scope Description
datatransport keepAliveSendIntervalSeconds Node Keep-alive send interval in seconds.
datatransport nonResponseTimeoutSeconds Node Non-response timeout in seconds.
datatransport deferredWritesEnabled Node Control deferred distributed writes.
engine timerParallelism Engine Timer execution parallelism.
engine timerResolutionMilliseconds Engine Timer resolution in milliseconds.
engine minimumDispatchThreads Engine Minimum number of dispatch threads.
engine maximumDispatchThreads Engine Maximum number of dispatch threads.
engine shutdownTimerSeconds Engine The engine shutdown timer in seconds.
eventbus noDestinationTimeoutSeconds Node The time in seconds to wait for an engine to start when dispatching work.
flusher flushIntervalSeconds Node The shared memory flusher wakeup interval in seconds.
flusher maximumObjectsPerType Node The maximum number of objects to flush per flush interval.
memorythrottle thresholdPercentage Node The percentage of shared memory utilization at which to throttle.
memorythrottle checksPerSecond Node The number of checks per second for the memory throttle threshold.
transaction timeoutSeconds Node Distributed deadlock timeout value in seconds.
transaction numberCompletedTransactions Node Number of completed transactions to maintain in the transaction history.
transaction maximumBackoffMilliseconds Node Maximum amount of time, in milliseconds, the deadlock back-off algorithm waits before retrying a transaction.

epadmin get tunable

Retrieves current tunable variable values. 

epadmin [sn|ad] get tunable
epadmin [sn|ad] get tunable --category=engine
epadmin [sn|ad] get tunable --name=engine.timerParallelism
Command Parameter Description Required
category Category name filter. No. Default value is all categories.
name Variable name filter. If you specify name as categoryName.variableName, you cannot also specify category. If you specify name as variableName, you must also specify category. No. Default value is all variables.

epadmin reset tunable

Resets a tunable value to its initial value. 

epadmin [sn|ad] reset tunable --name=engine.timerParallism
epadmin [sn|ad] reset tunable --name=engine.timerParallelism scope=application::JVMEngine1

reset command parameters

Command Parameter Description Required
name Variable name filter, specified as categoryName.variableName. Yes.
scope Variable scope, either literal Node or a valid engine name expressed as application::engineName. No. Default value is Node.

epadmin set tunable

Sets a tunable variable to a specified value. 

epadmin [sn|ad] set tunable --name=engine.timerParallelism --value=4
epadmin [sn|ad] set tunable --name=engine.timerParallelism --value=4 --scope=application::JVMEngine1
Command Parameter Description Required
name Variable name filter, specified as categoryName.variableName. Yes.
value Variable value, which can be a simple value or an array. Arrays are specified as comma-separated values. An array element that contains a comma must be enclosed in single quotes. Yes.
scope Variable scope, either literal Node or a valid engine name expressed as application::engineName. No. Default value is Node.

SEE ALSO

Help System for epadmin
epadmin(1)
epadmin-globals(1)